Using one-dimensional and two-dimensional Particle-In-Cell simulations, generation of elliptically polarized electromagnetic soliton is studied with the EPOCH-4.17.10 framework when a plane-polarized laser interacts with a plasma having linearly varying density under the presence of an external magnetic field applied in the direction of laser propagation. At the resonance absorption where the plasma frequency \({\omega _{pe~}}\) almost equals the laser frequency \({\omega _l}\) the plasma receives the most energy from the laser that became elliptically polarized in plasma. Near the critical density a density hill is developed where the electromagnetic field is confined, and the soliton is generated. This structure reflects back due to the density gradient after penetrating a small distance in the plasma in the direction of laser propagation, and it retains its shape for a longer period. In the case of larger slope in the density variation, the soliton generates towards the region, where plasma medium faces the laser launching. In addition, the position of soliton generation shows a dependence on the laser intensity. On the other hand, soliton height decreases and its width increases as the temperature of plasma species rises. The magnetic field effects are also found to be prominent, reducing the soliton height and broadening its width.
